A dongle is an encryption product of combination of hardware and software, which is inserted on a computer. As a tool with function of protecting software, the dongle may prevent, by protecting the software and data, the software from being illegitimately used. A software developer may perform data exchange through an interface function and the dongle, i.e., may perform writing or reading on the dongle. With an inbuilt single chip microprocessor circuit, the dongle has determination and analytical ability, and active anti-decryption ability of the dongle is accordingly enhanced. However, due to incorrect use of the dongle by a developer, a cracker may simulate the dongle with a pirated dongle by means of tracking and modulating. The cracker may run encrypted software by using the pirated dongle, which brings security vulnerability to user data.